Session 8-Lumbar Spine Structure, Function And Common Disorders Flashcards
How many:
1) cervical
2) thoracic
3) lumbar
4) sacral
5) coccygeal vertebrae are there?
1) 7
2) 12
3) 5
4) 5
5) 4
How many separable single vertebrae are there?
24
Which are the most mobile areas of the spine?
Cervical
Lumbar
Which area of the spine is relatively immobile and why is this?
Thoracic
Ribs attached limits movement
Which two parts of the spine are fusions of vertebrae?
Sacrum
Coccyx
What are the functions of the vertebral column?
- supports skull, pelvis, upper limbs and thoracic cage
- protection of spinal cord and cauda equina
- movement: highly flexible structure of bones, intervertebral discs and ligaments
- haemopoiesis: red marrow
True or false: vertebral bodies decrease in size inferiorly
FALSE - increase in size as compression forces increase
Why are the sacral vertebrae fused, widened and concave anteriorly?
To transmit weight of body through pelvis to legs
Which movements does the lumbar spine allow?
Flexion and extension
Lateral flexion
Rotation
What is the largest part of the vertebra?
Vertebral body
What is the vertebral body made up of?
10% cortical bone
90% cancellous bone
What are the advantages of having a higher proportion of cancellous bone in the vertebral body?
1) lighter
2) other functions ie haemopoiesis
What are end plates?
Articular surfaces covered with hyaline cartilage on superior and inferior parts of vertebral column
What connects transverse process to spinous process?
Lamina
What connects transverse process to body?
Pedicle
What is the lamina and pedicle called collectively?
Vertebral arch
What emerges through intervertebral foramina?
Spinal nerves
What is the articulation of superior and inferior articular processes called?
Facet joint (synovial)
What does the interlocking design of facet joints prevent?
Anterior displacement of vertebrae
What is the composition of intervertebral discs?
70% water
20% collagen
10% proteoglycans
Why do we lose height with age?
Repair of proteoglycans is less with age so chains get shorter so less hydrophilic and lose water and discs lose height
What is the role of proteoglycans in intervertebral discs?
Binds water (hydrophilic)
What are the two regions of intervertebral discs?
Nucleus pulposus (central) Annulus fibrosus (peripheral)
What is annulus fibrosus made of?
Type I collagen
What is the major role of annulus fibrosus?
Shock absorber
True or false: intervertebral discs are avascular
TRUE
What is the nucleus pulposus a remnant of?
Notochord
What is nucleus pulposus made of?
Type II collagen
When are intervertebral discs very strong?
Axial compression
What do the ligaments of the vertebral column provide?
Stability
What are the major ligaments of the vertebral column and which is stronger?
Anterior longitudinal and posterior longitudinal ligament
Anterior is stronger
What is the function of the anterior longitudinal ligament?
Prevents hyperextension
What does the posterior longitudinal ligament prevent?
Hyperflexion
What makes ligamentum flavum yellow?
Elastic fibres
What is the role of ligamentum flavum?
Limits hyperflexion
What do interspinous ligaments do?
Unite spinous processes
Where are the supraspinous ligaments?
Tips of adjacent spinous processes
Describe the curvatures of the vertebral column
Cervical - lordosis (curves backward) Thoracic - kyphosis (curves forward) Lumbar - lordosis Sacral - kyphosis Coccyx - kyphosis
What is the primary curvature?
Curve we’re born with-kyphosis
What are the ‘weak points’ of the vertebral column?
Where the centre of gravity pass through the vertebral column (C1, C2, C7, T1, T12, L1, L5, S1)
Where is there an exaggeration of lordosis during pregnancy?
Lumbar region
What is mechanical back pain?
Pain when spine is loaded
When is mechanical back pain:
1) worse
2) relieved?
1) exercise
2) rest
What are the predisposing factors of mechanical back pain?
Overweight
Unhealthy lifestyle
Deconditioned core muscles
How does decreased disc height lead to pain?
Decreased height -> increased stress on facet joints -> osteoarthritis -> pain
What are the four stages to disc herniation?
1) degeneration (ageing)
2) prolapse (protrusion of nucleus pulposus into spinal canal)
3) extrusion (nucleus pulposus breaks through annulus fibrosus)
4) sequestration (nucleus pulposus breaks through annulus fibrosus and separates from main body of disc in spinal canal)
Where is the most common location of slipped discs?
L4/5 or L5/S1
What is sciatica?
Compression of nerve roots which contribute to sciatic nerve
Which nerve roots contribute towards sciatic nerve?
L4 L5 S1 S2 S3
What are the types of sciatica?
L4 sciatica - anterior thigh, anterior knee and medial shin
L5 sciatica - lateral thigh, lateral calf and dorsum of foot
S1 sciatica - posterior thigh, posterior calf, heel and sole of foot
What is cauda equina syndrome?
Compression of cauda equina
What are the symptoms of cauda equina syndrome?
Bilateral sciatica
Perianal numbness
Painless retention of urine
Urinary/foecal incontinence
What is lumbar canal stenosis?
Narrowing of spinal canal in elderly due to:
- Disc bulge
- Arthritis in synovial facet joints
- Ligamentum flavum expands and restricts space for nerves
What is claudication?
Pain in legs when walking
What is spondylolisthesis?
Slip forwards of vertebra above on vertebra below
What are the types of spondylolisthesis?
- dysplastic: abnormality in shape of facet joints
- isthmic: defect in pars interarticularis
- degenerative
- iatrogenic
- pathological (tumours)
What does a patient with isthmic spondylolisthesis present with?
Back pain and L5 sciatica
What does a patient with degenerative spondylolisthesis present with?
Claudication
